A known gas sensor that detects the concentration of oxygen or NOx in an exhaust gas of, for example, an automobile includes a plate-shaped sensing element that uses a solid electrolyte.
This type of gas sensor, which is widely used, includes electrode pads disposed on a rear-end-side outer surface of the plate-shaped sensing element, metal terminals are in electrical contact with the respective electrode pads to output a sensor output signal from the sensing element to the outside, and power is supplied to a heater stacked on the sensing element (Japanese Unexamined Patent Application Publication No. 2015-129727 (FIG. 5)).
As illustrated in FIG. 19, a metal terminal 200 has a U-shaped section formed of strips, for example, in a manner in which a metallic plate is cut and raised, and a part thereof on a front-end side of a primary surface 200a is folded toward the sensing element (not illustrated) and forms a folded portion 202 that is elastically connected to one of the electrode pads of the sensing element. A crimping portion 204 for crimping an end of a lead wire is formed on the rear-end side of the metal terminal 200. The metal terminal 200 itself is inserted and held in an insertion hole 1300h of a ceramic separator 1300.